Note to Fox Broadcasting: thank you for allowing “Fringe” to come to a conclusion. Though its ratings were mediocre, you gave us five seasons of a science-fiction classic. Other networks should learn from you. One hundred episodes — an “eternity” for a TV show — is the magic number for the successful syndication of a series. But Fox’s patience is even more important because it allowed the cliff-hanging series to end on a grace note. Usually networks leave fans of low-rated, serialized series dangling over the precipice, alienating viewers along the way. And the traditional networks certainly don’t need to be hacking anyone off considering all the competition from cable channels, Netflix, the Web, etc. Abruptly canceling, say, a sitcom may not be a big deal if the show doesn’t have dangling plot lines. However, killing serialized shows without giving closure infuriates viewers.

My first personal experience with this came with the show, “Nowhere Man.” This TV series ran 1995-1996 on UPN, but wasn’t renewed for a second season. (UPN was a television network that was broadcast in over 200 markets in the United States from 1995 to 2006. In 2006, it merged with the WB, which morphed into the CW). “Nowhere Man” — whose premiere episode is arguably the best TV pilot ever; check it out here — is the story of photojournalist Thomas Veil (played by Bruce Greenwood), who goes to the bathroom in a restaurant and comes out to discover his life has been erased. His friends claim not to know him; his wife claims not to recognize him; his ATM cards and credit cards no longer work. In other words all evidence of his existence has disappeared in a matter of minutes. Tom believes this is a conspiracy related to a photograph he took a year earlier, depicting four men being hanged in South America by what appear to be U.S. soldiers.

“Nowhere Man” was a fascinating, surreal show. Fifteen years later I’m still wondering what the heck was going on. (I have geek dreams of J.J. Abrams resurrecting the show.)

Over the years there have been other shows that have let down viewers wishing for a conclusion: “Twin Peaks” (1990-1991, ABC) “Strange Luck” (Fox, 1995-1996), “Threshold” (2005, NBC), “Invasion” (2005, ABC), “Pushing Daisies” (2007-2009, ABC), “The Event” (2010-211, NBC), the relaunched “V” (2009-2011, ABC), “Alcatraz” (2012, Fox) and many others. (As you can see, most of the shows have a science fiction slant — at least the ones I recall).

I’m not expecting TV networks to allow low-rated shows to continue. After all, television is a business. However, there ought to be an unwritten, understood agreement between networks and viewers that a serialized show will be given the opportunity to wrap up its plot lines, either through a few extra episodes or perhaps a two-hour movie. This happened with “The Fugitive” TV series in the 1960s and, lately, “Fringe” — but these are exceptions to the rule.

Offering closure will generate enormous good will among viewers. And that’s good business. If networks continue to flip the bird to viewers, we’ll quit watching your dramas and turn to HBO, FX, ShowTime, etc., for such fare. Of course, the networks may not care. If we quit watching their dramas, they’ll fill our screens with cheaper-to-produce comedies and still more atrocious reality shows. This will eventually lead to the collapse of civilization. So tell me, ABC, CBS, NBC, and, yes, you too, Fox do you really want that on your conscious?